Spurs scored three times in seven minutes to overturn a one-goal deficit and defeat City on Sunday, giving their hopes of Champions League qualification a massive boost in the process.
Friedel believes that City's capitulation points to a wider problem at the Etihad and is a prime example of why Manchester United were able to reclaim the Premier League title with relative ease.
He told The Mirror: "Football is strange. Something like that hasn't happened very often to an Alex Ferguson team, that's for certain.
"On Sunday, it seemed that if the game had gone on for another 20 minutes we'd have gone on to score five or six. There was a really strange feeling in the ground, from the City side, it seemed that as soon as we scored the first goal it was almost as if they were deflated and felt they had lost the game, even though it was only still 1-1.
"I don't know what goes on behind the scenes and behind closed doors there, but it's very rare to see anybody score three in 15 minutes against Manchester United, that's for sure."
Spurs sit fifth in the Premier League, a single point behind Chelsea in the final Champions League place.